The field of the invention comprises inflatable balls used in a variety of sports such as football, basketball, soccer, etc. In particular, the invention pertains to the bladder valve used to inflate and reinflate such a ball.
Typically, such inflatable balls are constructed with an outer leather or vinyl cover and an internal rubber air bladder. The bladder includes a rubber valve that is opened by a hollow needle inserted to inflate the ball. The valve closes or reseals as the hollow needle is withdrawn. Such valves are disclosed in U.S. Pat. No. 2,731,028. Other types of bladder valves are disclosed in U.S. Pat. Nos. 2,349,463, 2,387,433 and 3,107,683.
Unfortunately, bladder valves, being constructed with rubber components, weaken with age and hard usage. The ball then tends to go soft regularly and necessitate replacement at considerable expense before the exterior of the ball is worn out.